The present embodiments relate to medical ultrasound imaging catheters. An acoustic array is positioned in a catheter. The catheter is positioned in the patient, such as in the heart of the patient. The patient is scanned using the acoustic array, providing real-time images from within the patient. The ultrasound imaging may assist with diagnosis or treatment. However, the flexibility of the acoustic array may result in artifacts in the image. The images may have speckle noise or other artifacts, so it may be difficult for a physician to relate the ultrasound image to the region to diagnose or treat.
Fusing fluoroscopy with the ultrasound imaging provides more information for diagnosis or treatment. The patient and catheter are imaged using x-rays. To register the fluoroscopy imaging with the ultrasound imaging, the catheter is located within a fluoroscopy image. Location of the catheter may be difficult to determine, so radio opaque markers are added to the catheter. The markers allow more precise location identification of the catheter in the fluoroscopy image. Accurate placement of the markers is needed.
The markers are positioned during catheter construction. The catheter housing is formed over the markers and relied on to hold the markers in place. However, the housing is not stable or flows during the construction of the catheter. The markers positioned in the catheter during the construction may change position, leading to inaccuracies in registration of the fluoroscopy and ultrasound images.
For tracking an imaging catheter with magnetic position sensors, a metallic stiffener is provided in the catheter. The stiffener may improve imaging while also improving the orientation of the magnetic position sensors and the acoustic array.